General Tracking Information

Overall, 17.32% of samples had a recorded gaze position.

The total number of blocks in this design was 105. This was calculated as the number of trials multiplied by the number of blocks within each trial.

Out of those blocks, 0 were completely missing data. These missing blocks can be seen below:

trials_this_n block n tracked perc

The percent of samples tracked within each block can be seen below:

trials_this_n block n tracked perc
0 fixation 978 815 83.33
0 stimulus 3499 2538 72.54
0 text 3009 1687 56.07
1 fixation 992 474 47.78
1 stimulus 3499 1028 29.38
1 text 3002 1550 51.63
2 fixation 981 1 0.10
2 stimulus 3500 1868 53.37
2 text 3010 866 28.77
3 fixation 990 346 34.95
3 stimulus 3500 2926 83.60
3 text 3003 2105 70.10
4 fixation 981 981 100.00
4 stimulus 3499 2143 61.25
4 text 3007 2149 71.47
5 fixation 976 856 87.70
5 stimulus 3501 1420 40.56
5 text 3007 1031 34.29
6 fixation 976 915 93.75
6 stimulus 3500 692 19.77
6 text 3009 1216 40.41
7 fixation 992 916 92.34
7 stimulus 3499 1874 53.56
7 text 3011 481 15.97
8 fixation 989 0 0.00
8 stimulus 3499 0 0.00
8 text 3011 0 0.00
9 fixation 989 0 0.00
9 stimulus 3501 0 0.00
9 text 3010 0 0.00
10 fixation 990 0 0.00
10 stimulus 3499 0 0.00
10 text 3011 0 0.00
11 fixation 989 0 0.00
11 stimulus 3501 0 0.00
11 text 3011 755 25.07
12 fixation 989 898 90.80
12 stimulus 3500 178 5.09
12 text 3009 896 29.78
13 fixation 992 549 55.34
13 stimulus 3498 1006 28.76
13 text 3004 262 8.72
14 fixation 980 571 58.27
14 stimulus 3499 172 4.92
14 text 3005 0 0.00
15 fixation 979 0 0.00
15 stimulus 3499 255 7.29
15 text 3011 0 0.00
16 fixation 991 0 0.00
16 stimulus 3498 0 0.00
16 text 3011 99 3.29
17 fixation 989 0 0.00
17 stimulus 3500 0 0.00
17 text 3010 903 30.00
18 fixation 991 282 28.46
18 stimulus 3499 379 10.83
18 text 3010 173 5.75
19 fixation 990 0 0.00
19 stimulus 3500 0 0.00
19 text 3007 0 0.00
20 fixation 977 0 0.00
20 stimulus 3500 0 0.00
20 text 3008 0 0.00
21 fixation 976 0 0.00
21 stimulus 3499 0 0.00
21 text 3010 0 0.00
22 fixation 991 0 0.00
22 stimulus 3499 0 0.00
22 text 3008 0 0.00
23 fixation 976 0 0.00
23 stimulus 3499 0 0.00
23 text 3009 0 0.00
24 fixation 974 0 0.00
24 stimulus 3500 0 0.00
24 text 3009 0 0.00
25 fixation 974 0 0.00
25 stimulus 3500 0 0.00
25 text 3004 0 0.00
26 fixation 981 0 0.00
26 stimulus 3498 0 0.00
26 text 3008 0 0.00
27 fixation 976 0 0.00
27 stimulus 3500 0 0.00
27 text 3010 0 0.00
28 fixation 991 0 0.00
28 stimulus 3499 0 0.00
28 text 3009 0 0.00
29 fixation 975 0 0.00
29 stimulus 3500 0 0.00
29 text 3008 0 0.00
30 fixation 992 0 0.00
30 stimulus 3482 0 0.00
30 text 3010 0 0.00
31 fixation 991 0 0.00
31 stimulus 3499 2948 84.25
31 text 3003 2214 73.73
32 fixation 980 641 65.41
32 stimulus 3500 1364 38.97
32 text 3005 0 0.00
33 fixation 978 0 0.00
33 stimulus 3501 0 0.00
33 text 3008 0 0.00
34 fixation 975 0 0.00
34 stimulus 3500 0 0.00
34 text 3014 0 0.00

Gaze Position

All gaze position data is taken after the instructions were completed. Presented data is average gaze position as given by the eyetracker. Samples where no eyetracking data is recorded are removed from the overall count.

  • % of time participant was gazing on screen: 90.9%.
  • % of time participant was gazing within the stimulus area during stimulus blocks: 90.32%.

Pupil Size

Distribution of Pupil Sizes

Eyelink reports pupil data from left and right eyes as well as the average of the two. The preprocessing pipeline performs mean and median normalization on all 3 measures relative to prefixation and fixation baselines. The following plots show the distribution of pupil sizes for samples where the participant has their gaze on the screen during the experiment (i.e. past the instructions block).

Pupil Sizes During Stimuli

Epoch Median

Median average (combined left and right values) pupil size is plotted for each stimulus block as a function of epoch. Raw values are plotted followed by prefixation and fixation-normalized values, respectively. Within stimulus blocks, patterns of change in pupil size are not different across the raw and two types of normalization, however the differences pupil size between blocks does differ across normalizations. The extent to which they differ is dependent on the variance in pupil size during the chosen normalization block across samples.

Pupil Size and Gaze Position

Median average pupil size are plotted as functions of gaze position during stimulus blocks. Only positions within the boundary of the stimulus area are plotted. Non-normalized median values are plotted first followed by prefixation normalized, and then fixation normalized.

Raw Pupil Size

Prefixation Normalized

Fixation Normalized